The mainstream press holds transit projects to a higher cost-effectiveness standard than highways, as recent coverage of the proposed Columbia Pike streetcar demonstrates.

In reality, the streetcar is a relative bargain purely on the basis of direct cost per estimated user, not even including the external costs of sprawl and pollution that new and improved highways engender.

Last week, Arlington County raised the streetcar’s cost estimate to between $242 million and $261 million, citing “inflation, an increase in the scope of the proposed project, additional engineering requirements, and federal requirements for higher contingency funding and escalation.”

But focusing only on the cost increase obscures that, on a per-mile or per-user basis, the streetcar still costs much less than other projects:

Beltway HOT lanes: $1.4 billion for 14 miles and estimated 66,000 users per day

Maryland Intercounty Connector: $2.6 billion for 18 miles and estimated 30,000 users per day

These simple figures don’t even include the huge cost to road users of buying, fueling, maintaining, and insuring a car. They also omit the massive air quality, public health, climate change and other costs of vehicle pollution, and the strains on open space and government services that come from the sprawling development this highway building enables.

The streetcar’s mere $261 million price tag, by contrast, covers a 5-mile segment to be used by an estimated 26,000 riders per day.

Instead of further straining public resources by feeding sprawl, the Columbia Pike Streetcar is expected to help revive an existing commercial corridor, contributing positively to Arlington County’s balance sheet over time as new development produces tax revenue while adding minimal costs to county services. “County officials believe that by 2040, 3,900 residences and 2.2 million square feet of commercial development, with 7,000 new jobs, will be added,” reports the Post.

Yes, $261 million is a heavy lift at a time of economic uncertainty, but a generation ago, so was Metrorail. “Lots of people were vehemently against an infrastructure investment of that magnitude at that time — especially when the decision was made to move it off I-66 and put it underground, which cost that much more,” Arlington County Board Member Jay Fisette told me in an interview. “If any community should be able to point to a historical experience of why this kind of investment is worth it for economic impact, quality of life and community planning value, it’s Arlington.”

More broadly, the Columbia Pike Streetcar is part of the region’s next generation of transportation, along with Maryland’s Purple Line and a mix of new and revived DC lines. Streetcars are cheaper and have a smaller footprint than Metro’s existing heavy rail, while enticing more riders than buses.

County officials say they’re hoping to get word on a federal funding commitment to the streetcar in 2012, which would put it on pace for a 2014 groundbreaking and a 2016 opening. From there, extensions to Falls Church or Alexandria are possible.

"The community has endorsed this for years,” said Fisette. “As we continue to refine this project and bring it towards the finish line, I’m confident it will be good for Columbia Pike, our economy, our quality of life, and for beginning the next generation of regional rail.”

Miles Grant grew up in Boston riding the Green Line, and has lived in Northern Virginia riding the Orange Line since 2002. Also blogging at The Green Miles, he believes enhancing smart growth makes the DC area not just more environmentally sustainable, but a healthier and more vibrant place to live, work and play.